Ibeg leave through your hands to welcome my brethren of the Linnean Society on their first meeting for the ensuing season, and to communicate at the same time an article of botanical intelligence rather interesting to those who are solicitous about natural genera, as well as to those who have endeavoured to ascertain the plants of ancient Greek authors.

Jacquin in his Hortus Vindobonensis, v. 1.35. t. 81, has described and figured a plant by the name of Sempervivum sediforme, which subsequent compilers of botanic system have implicitly adopted by that name. It has even found its way into the Hortus Kewensis, v. 2.149, being far from uncommon in the English gardens, where it flowers copiously every summer in the open ground. The excellent author above mentioned remarks, that "the appearance of its leaves" (he might have said its whole habit) "is that of a Sedum," but that "the flower has exactly the character of a Sempervivum, the petals being 6 or 7, with broad bases, and an equal number in the parts of the calyx, as well as the germens, and double the number of stamens." He also asserts that "there are no nectariferous scales."

The plant has so entirely the appearance of a Sedum and not of a Sempervivum, and I have always thought those genera so natural, and so well marked by the technical character of nectariferous scales at the base of the germen in the former, which the latter wants, that I have often regretted to read Jacquin's account, which I presumed was correct. But meeting with this plant in Dr. Sibthorp's Greek herbarium, it became necessary to investigate its characters myself. In the winter time I could only examine one of his specimens by means of hot water; but there, to my great satisfaction, I found the nectariferous scales as evident as in any Sedum whatever; and on dissecting living flowers last summer in my garden, the same character was every where obvious. In number of parts indeed this flower wanders a little from the character of that genus, and from its class Decandria having often, when cultivated, as many petals, stamens and pistils as Jacquin describes, or even more, though this is chiefly the case in the first flowers of the cyme, and not so much in the external ones. I have therefore introduced the plant in question into the second part of the Prodromus Floræ Græcæ, p. 312, by the name of

Dr. Sibthorp, who was well acquainted with his learned friend Jacquin's plant, mentions it in his papers as one of the most

common species in various parts of the continent of Greece, as well as in almost all the Greek islands, growing on rocks and walls near the sea-side. At Athens it is pounded and applied as a cooling cataplasm to bruises or to gouty limbs, being called Κολλωςιδα by the Athenians of the present day. Its most general names however in modern Greek are Αμάραντο and Σταφυλάκι.

The three species of Αειζωον of Sempervivum in Dioscorides seem to have been misunderstood. The 1st, Αειζωον το μεγα, hitherto taken by Matthiolus and others for the Common House-leek, Sempervivum tectorum, is justly referred by Dr. Sibthorp, as well as Clusius, to Sempervivum arboreum, with which the description of Dioscorides, more full than usual, most admirably agrees, and not at all with the tectorum. The 2d, Αειζωον το μικςον, or Sempervivum minus, was taken by Matthiolus for Sedum album, and by Dr. Sibthorp, not without much doubt, for Sempervivum hirtum; but I have no scruple at all in referring it to my present Sedum ochroleucum, a plant probably not known to Matthiolus. Dioscorides says "it grows on walls, stones and banks, as well as about shady enclosures. Several slender stems," he adds, "spring from one root, thickly encompassed with little round succulent sharp-pointed leaves. It throws out, moreover, a stem towards the middle, about a span high, with an umbel of slender (greenish or) pale yellowish flowers. Its leaves have the same virtues with the former."—The virtues alluded to of "the former," or Sempervivum arboreum, are cooling and astringent; whence Dioscorides recommends that plant in inflammatory eruptions and the gout, for which the Sedum ochroleucum is used at present, as mentioned above.

The 3d, Αειζωον ἑτερον, which is described as "heating, acrid and exulcerating, with very small thick leaves," seems to be Sedum acre, as Matthiolus and Clusius judged, though Dr.

Sibthorp took it for our Sedum ochroleucum, on the authority of a figure in the celebrated Imperial manuscript of Dioscorides at Vienna, which he considered as of great authority. The qualities however recorded of this 3d Αειζωον are quite at variance with those which Dr. Sibthorp himself attributes to the Sedum ochroleucum, and which agree with those ascribed by Dioscorides to his second species.